Undifferentiated embryonal sarcoma of the liver in children: our experience in four difficult cases and three-dimensional practical exploration

Abstract Aims To explore the rare and difficult cases of undifferentiated embryonal sarcoma of the liver (UESL) in children in a single center, summarize the diagnosis and treatment experience and analyze the role of the computer-assisted surgery system (Hisense CAS), providing a new global vision and three-dimensional perspective. Methods We retrospectively collected the clinical data, diagnosis, and treatment process of children with UESL confirmed by histopathological examination in our hospital from January 2009 to December 2020. The relationship between the tumor and important blood vessels, liver and tumor volume, as well as other three-dimensional characteristics in the three-dimensional model reconstructed by Hisense CAS were analyzed. The findings from this analysis help in making surgical decisions and preoperative planning. Results Four children with UESL were included in the study, comprising of 3 girls and 1 boy. The age of onset ranged from 6 to 8 years. All four children presented with symptoms of abdominal discomfort, and abdominal masses were detected during physical examination. Due to the urgent wishes of their parents and the possibility of a benign disease, all four children underwent one-stage radical surgery. In Case 1, three-dimensional reconstruction was not performed during the initial diagnosis, which made it challenging to accurately evaluate and plan the preoperative procedure. Case 2 presented additional challenges as the tumor was located in the middle lobe of the liver and involved the first and second hepatic hilum. Case 3 faced difficulties in the pathological diagnosis of the tumor after surgery, but eventually, the diagnosis was confirmed through histochemistry and consultation with higher-level hospitals. Case 4 had a gaint tumor, and the preoperative simulated future liver remnant volume (FLV) accounted for 21.0% of the total volume of liver and tumor (TLTV). According to the standard liver volume (SLV) for children, the FLV accounted for 77.0% of the SLV, making surgery feasible. Although all four children underwent complete resection, Case 4 experienced recurrence below the diaphragm 19 months after surgery. Currently, the 3-year overall survival rate stands at 100%. Conclusion UESL in children is clinically rare, and the key to diagnosis and treatment lies in complete surgical resection. By utilizing individualized three-dimensional surgical planning, accurate and complete resection of difficult and complex UESL cases in children can be achieved, leading to a favorable prognosis.